1. Field of the Invention
The invention relates to a means of quickly securing and removing plates on and from the ends of barbells, dumbbells, and similar exercise equipment without the use of separable collars.
2. Prior Art
Exercise and physical activity are important and beneficial for long-term health and well-being. Strength training is an important component of exercise and can be done with calisthenic exercises such as push-ups, free weights such as barbells and dumbbells, or resistance machines.
Free weights are favored by many fitness enthusiasts because they recruit more muscle groups than resistance machines, which tend to only isolate specific muscles. Free weights are also more versatile than machines because they allow for more variations in range of motion, require balance, and tend to promote more activity of the joint stabilizer muscles. Finally, they are considerably less expensive than most of the machines on the market.
The two common forms of free weights are barbells and dumbbells. Barbells are typically designed with one or more weights disposed at each end of a bar and are intended to be lifted with two arms. Dumbbells are similar but have a shorter bar and are intended to be lifted with one arm. These devices are used during the course of various exercises to increase strength by providing resistance to muscles.
For reasons of economy and versatility, it is advantageous to be able to change the weight at the ends of the bars to vary the resistance provided by the exercises. The most common means of doing this is by using disc-shaped plates with central openings that enable them to be slid onto the ends of the bars. These weights are typically retained on the weight bar by placing them against a stop fixed on the inward portion of the bar and securing the weights with a collar that can be placed adjustably on the outer end of the bar and locked into place with set screws or clamps. The drawback associated with collars is that many users of barbells and dumbbells omit the use of collars to save time when changing plates. This practice can be hazardous since tilting the bar from a horizontal position can cause the weight or weights at the lower end of the tilted bar to slide off and seriously injure the user and adjacent persons. Another problem with collars is that they permit the plates to spin, slide, wobble, and rattle which can interfere with control of the barbell during exercises. Collars are also subject to being misplaced or lost.
Other means of securing collars include threads such as disclosed in U.S. Pat. Nos. 4,638,994 and 4,529,197 to Gogarty, serrated flanges that interact with threads on the bar such as disclosed in U.S. Pat. No. 4,738,446 to Miles; and pistons which in fit into recesses in the bar such as disclosed in U.S. Pat. No. 5,605,411 to Wilson. These forms of the prior art provide an alternate means of means of attaching collars to the weight bar but do not substantially negate the drawback associated with conventional collars.
Other prior art addresses the problem of adjustable weight dumbbells and barbells through free weight assemblies that engage the plates by mechanisms that are more sophisticated than collars. Examples are disclosed in U.S. Pat. No. 4,284,463 to Shields (dumbbell assembly having opposite side weights which are connected to a handle by cam driven pins on the weights); U.S. Pat. No. 4,529,198 to Hettick, Jr. (barbell assembly having opposite side weights which are connected to a handle by means of axially movable springs); U.S. Pat. No. 4,822,034 to Shields (barbell and dumbbell assemblies having opposite side weights which are maintained on a shelf and connected to a handle by means of latches on the weights); U.S. Pat. No. 5,839,997 to Roth et al. (dumbbell assembly having opposite side weights which are connected to a handle by means of eccentric cams on a rotating selector rod); U.S. Pat. No. 6,682,464 to Shifferaw (dumbbell/barbell with a bar and a plurality of weights mounted on the bar which are hinged together and can be separated for disengagement from the bar); and U.S. Pat. No. 6,669,6063 to Krull (weight supporting members are rotated into engagement with respective weight plates). A problem with this form of the prior art is that such devices require plates of proprietary design. Many users of exercise equipment already own standard types of commercially-available plates and therefore using this form of the prior art would require them to entail additional expense.
Objects and Advantages
There is a need for exercise devices that can use standard types of plates and that do not require separable collars. The present invention accomplishes this aim and is suitable for using in the form of standard weight bars which have a diameter of about 1-inch and on Olympic style weight bars in which rotatable sleeves that are about 2-inches in diameter are attached at the ends of a solid bar of about 1-⅛-inch diameter.
Some of the objects and advantages of the present invention are:
(a) to provide a means of securing plates that is convenient and quick to use;
(b) to provide a means of securing plates that prevents them from spinning, sliding, wobbling, or rattling;
(c) to provide a means of securing plates that does not rely on collars or other separable securing devices that can be misplaced or lost; and
(d) to provide a means of securing plates that allows the use of conventional plates and thereby eliminates the unnecessary expense associated with proprietary pieces of weightlifting equipment.